In many industries it is desirable to determine properties of constituent particles of a sample of material. Such materials include powders, and aggregates such as granules, pellets and briquettes. One property of interest is the strength of constituent particles of a sample of material.
For instance, certain industries produce aggregates as finished or intermediate products and the strength of the aggregated product is important to the marketability of the product as breakdown of the product defeats the purpose of the aggregation operation. In the iron ore industry, aggregates in the form of pellets are individually tested for strength by controlled crushing. However such a technique is time consuming as the process occurs on a pellet by pellet basis. Furthermore, the technique is destructive as pellets are generally destroyed in the process. It is desirable to rapidly determine the average strength of the pellets, in bulk using a non destructive technique.
A further property of interest is the dusting characteristics of powders which is directly related to the strength of the particulates which make up the powder. Insufficient particulate strength leads to dusting, which may interfere with production line processing as clogged machinery will lead to a temporary shut down of the plant.
In the alumina industry, alumina powder is produced by the process of crystallisation and calcination. In order to test the strength of the particulates making up the calcined powder, a sample of the calcined powder is typically subject to an attrition test. This test involves mechanically shaking the sample and making successive measurements to determine the change in size of the individual particles. From this the strength is able to be calculated. Again, measurements on individual particles is time consuming. Furthermore, the measurement is performed on the calcined product. It is desirable to be able to determine the average properties of particulates of the material in bulk and prior to calcination.
Aggregates are also produced in many non-mineral industries such as food production and laundry detergent, powder manufacture. Thus, a wide variety of products are produced as aggregates in respect of which it may be desirable to determine material properties.